title: Implication of minimal extrathyroidal extension as a prognostic factor in papillary thyroid carcinoma.
abstract: OBJECTIVE
  Extrathyroidal extension (ETE) of papillary thyroid carcinoma (PTC) is a risk factor for tumor recurrence. By TNM Classification (7th edition), differentiated thyroid carcinoma with ETE is designated T3 (minimal invasion), T4a (extended invasion), or T4b (more extensive unresectable invasion), according to the degree of tumor involvement. We subsequently focused our investigation on minimal ETE (MEE), analyzing the clinicopathologic characteristics, recurrence rate, and recurrence-free survival (RFS) in this setting.
  
  
  METHODS
  A retrospective study was conducted, based on 332 patients undergoing thyroidectomy for PTC between January 2005 and December 2006.
  
  
  RESULTS
  The study population was stratified into two groups: PTC with MEE (103/332; 31.0%) and PTC without MEE (229/332; 69.0%). In patients with PTC, MEE correlated with gender, tumor size, multifocality, lymph node (LN) metastasis, underlying Hashimoto's thyroiditis, and the nature of the surgery. However, no significant intergroup differences were evident with respect to age, recurrence rate, and LN metastasis. In multivariate analysis, LN metastasis (odds ratio = 2.273; 95% confidence interval, 1.280-4.037) was recognized as an independent correlate of mETE (p = 0.005). However, recurrence-free survival did not differ significantly between the groups (p = 0.153), even when further stratified by the presence or absence of LN metastasis.
  
  
  CONCLUSIONS
  In patients with PTC, MEE does not impact RFS. Thus, appropriate surgical intervention and postoperative follow up are mandatory in PTC, regardless of its extent.
authors.affiliation: Department of Surgery, Busan Paik Hospital, Inje University, Republic of Korea.
authors.forename: Jae Ho
authors.initials: JH
authors.lastname: Shin
authors.forename: Tae Kwun
authors.initials: TK
authors.lastname: Ha
authors.forename: Ha Kyoung
authors.initials: HK
authors.lastname: Park
authors.forename: Min Sung
authors.initials: MS
authors.lastname: Ahn
authors.forename: Kwang Hee
authors.initials: KH
authors.lastname: Kim
authors.forename: Ki Beom
authors.initials: KB
authors.lastname: Bae
authors.forename: Tae Hyeon
authors.initials: TH
authors.lastname: Kim
authors.forename: Chang Soo
authors.initials: CS
authors.lastname: Choi
authors.forename: Tae Kyoon
authors.initials: TK
authors.lastname: Kim
authors.forename: Sung Kwon
authors.initials: SK
authors.lastname: Bae
authors.forename: Sang Hyo
authors.initials: SH
authors.lastname: Kim
mesh_terms: D000328:Adult; D000368:Aged; D002277:Carcinoma / Q000473:pathology* / Q000601:surgery; D002291:Carcinoma, Papillary; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000473:pathology; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors; D000077273:Thyroid Cancer, Papillary; D013964:Thyroid Neoplasms / Q000473:pathology* / Q000601:surgery; D055815:Young Adult
keywords: Minimal extrathyroidal extension; Papillary thyroid carcinoma; Recurrence; Recurrence-free survival